The present invention relates to a dethatching system for attachment to a tractor that includes a flail dethatching mechanism and catcher bag.
Properly maintaining a lawn or the like involves dealing with thatch which is an unattractive brown layer of dead grass and vegetation which covers the ground surface. Excess thatch can result in many troubles, such as, for example, encouragement of grass root development above the surface of the soil (within the thatch) promoting "brown-off" and winter injury, increase watering needs to maintain greenness of the grass, increase the difficulty of mowing when the "spongy" surface allows the mower wheels to sink down into the lawn, provides a home for insects and lawn disease, restricts water and air movement into and within the soil, and inhibits the downward movement of pesticides and fertilizers into the soil. Accordingly, the periodic removal of thatch is desirable to maintain a healthy green lawn.
Several devices have been developed in an effort to remove thatch from the ground surface. One of the most common devices used to remove thatch is a hand-held rake. The rake is drawn across the ground surface to dislodge the thatch and plant matter. Unfortunately, raking can be unpleasant, strenuous, and time consuming. Also, raking results in dislodged thatch that must be collected and removed to a appropriate location remote from the lawn.
Another type of dethatcher includes tines which do not rotate and are mounted in front of or behind a tractor. In such a device, a plurality of tines project vertically downward toward the ground from a horizontal surface secured to the tractor. As the tractor moves, the tines are drawn across the ground surface to loosen the thatch. Unfortunately, the tine tip speed is limited to the speed of the tractor which results in incomplete dethatching. Also, the vertically projecting tines tend to break and dig into the ground causing damage to the ground surface. Further, similar to using the rake, the dislodged thatch needs to be removed after dethatching. Accordingly, an expensive sweeper attachment for the tractor is required or additional time consuming effort must be taken to collect and remove the lawn debris.
Haban et al., U.S. Pat. No. 5,408,813, disclose a dethatching apparatus for attachment to the rear of a tractor. The dethatching mechanism consists of a set of circumferentially and axially displaced wire tines attached to a pair of axially aligned shafts. Each of the shafts are driven by a respective wheel of the apparatus via a respective gear. The dethatching apparatus includes a catcher bag positioned behind the tines for receiving thatch and plant matter. The tines are biased in an angular relation to the respective shaft by at least one integral spring. Accordingly, the impact force of the tine with the ground is limited to the speed of rotation of the shaft and the material from which the tine is constructed of. Moreover, the shafts are powered by the rotation of the wheels which makes the rotational speed of the shaft dependant on the speed of travel of the tractor. If the tractor moves too slowly then the tines will not have a tendency to impact the ground with an insufficient force to properly dethatch. Alternatively, if the tractor moves to quickly then the tines will not impact the ground properly for dethatching the grass. In either case, if the wheels are not making proper rotational contact with the ground, such as may occur over excessively rough and uneven ground surface, then the tines will not rotate at a suitable speed. In addition, the catcher bag receives the thatch and grass matter near its lower front region which results in a tendency for that portion of the catcher bag to fill thereby only partially filling the catcher bag before it will not accept more materials. Thus additional stops to empty the partially filled catcher bag may be necessary.
What is desired, therefore, is a tractor based dethatching apparatus where the tines impact the ground with a force that is independent of the speed of the tract or together with a combined catcher bag that will substantially fill with thatch and lawn debris prior while dethatching.